SUMMARY
Sometime it's handy to drag-and-drop some words from the original message to the translated one (e.g. identificators, and so on) if I don't have to translate them. This generally works, but if I first:

1. select a peice of my translated message with mouse;
2. left click on the selected characters, and drag them elsewhere in the same translated message;
3. then select a peice of the original message with mouse;
4. left click on the selected characters, and drag them in the translated message

...I see a weird behavior: some characters in the translated message will be deleted. It seems they were at the same position and in the same amount of those I've dragged.

EXPECTED RESULT
All the drag-and-drop operations should works.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20210614
KDE Plasma Version: 5.22.0
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2
Kernel Version: 5.12.9-1-default (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION
After that, all the drag-and-drop operations will be corrupted.